1. Field of the Invention
This invention relates generally to magnetic head assemblies and methods of manufacture therefor and, more particularly, to magnetic head assemblies having a magnetic read/write transducer and a pair of erase transducers.
2. Description of the Prior Art
Magnetic head assemblies have long been used for recording and reproducing bits of information on relatively moving magnetic mediums, such as magnetic discs, magnetic drums and magnetic tape. Magnetic discs may be either rigid or flexible. The rigid disc includes an aluminum disc-shaped substrate which is coated with a magnetizable material and which rotates at high speeds under a magnetic head assembly, thereby forming memory tracks arranged in a series of concentric circles about the center of the disc. In applications which require high data transfer rates, noncontact recording schemes have been used so as to avoid the wear problems associated with contact recording. In noncontact recording schemes, the magnetic heads are supported by a self-acting air bearing created between the head and the disc during relative rotation therebetween with the air bearing surface being designed to insure that the spacing is relatively constant. These flying heads are expensive to fabricate since extremely precise machining of the air bearing surface of the slider body is required in order to obtain the exact aerodynamic characteristics. Severe problems have also been encountered in positioning and bonding a magnetic transducer within the slider body.
In flexible disc systems, the magnetic medium comprises a flexible mylar substrate having magnetic material secured thereto to provide the recording surfaces. In recording and reproducing information in these systems, the magnetic read/write transducers contact the recording surface. To limit the width of the track written by the read/write transducers, the magnetic head includes erase transducers positioned on both sides of the read/write transducer which serve to erase the edges of the track immediately after it is written. Compliance between the transducers and the flexible medium is affected by utilizing pressure pads which continuously conform the disc against the contour of the transducing surface of the head assembly.
Heretofore, the magnetic head assemblies used in flexible disc drive systems have incorporated much of the technology developed for flying heads. For example, the head assembly has included separate erase transducers positioned adjacent the read/write transducer and having their gaps aligned parallel to and spaced apart from the gap of the read/write core to avoid cross coupling between the read/write and the erase transducers. In addition, the transducers have been bonded to the head assembly with epoxy. In epoxying the magnetic transducer components into the head assembly, many steps are involved and elaborate fixtures are required to hold the components in place during assembly. Because of the labor and fixturing involved, the assembly process is very expensive. In addition to the expense involved, another disadvantage is that because the erase gaps are spaced apart from the read/write gap to avoid cross coupling, circuits are required to delay the energization of the erase transducer relative to the energization of the read/write transducer. Also, because the erase gaps are parallel to the read/write gap, the read/write track cannot be easily trimmed to a width less than the width of the read/write core.